Adjustable intraoral tracer



Patented Aug. 17, 1948 ADJUSTABLE'INTRAORAL Tana En.

Fay E. Smith, Cleveland, Delmar'Lacer, Lakewood, and Clarion B. McLeod,Cleveland, Ohio,

assignors to Fay E. Smith,l )elmar Laccr, and Clarion B. McLeod, doingbusiness as Smith,

Lacer,

McLeod Dental Laboratories,'Cleveland,

Ohio, a partnership of Ohio I v Application June 2 1947, S erial No.757,144 f invention relates to the manufacture of dental plates, andmore particularly towhat is known as an adjustable, intra-orail tracer,the purpose of which is to assist the dentist and laboratory technicianin, so shaping and forming the plates as to insure. proper verticalspacing between the jaws and thus not only secure correct bite but alsopreserve or produce the most desirable'contour of the lips, cheeks andother soft tissues. I

One object of the invention is to provide an improved tracer of simpleform, capable of repeated, use, and adapted for adjustment while theplate models are .within the oral cavity, .Another object is to. providea tracer of the character described which is very compact, which may bemolded in situ as a partof a bite plate, and whichtherefore isadjustable while in place in the oral;cavity. .Still 'another object isto provide a tracer including a stem vertically adjustable to determineproper-plate spacing, together with simple and eifective mechanismincluding a memberextending outwardly through the mouth opening foradjusting said stem.

Finally, anotherobject is to provide animproved tracer of such form as:to simplify-and improve the present technique in the construction' ofdental plates, as will more ruuy appear hereinafter. I I 1Furtherobjects of the invention'in part are obvious andiin part willappear more in detail hereinafter.

a In the drawings, 1

Fig.- lreprese'nts a sideelevation of a portion of the face; with thejaws closed, and showing the protruding operating shaft-of our improvedtracer; g I Fig. 2 is a similar view, but with some of the soft tissuesin section to expose the bite plates;

Fig. 3 is a front elevation of a pair of bite;

plates formed andequipped according to our invention;

Fig. 4 a sectional elevation on the line 4-4,"

Fig. 3, but showing the tracer in elevation;

Fig. 5 is a bottom plan view looking upwardly along the line 5-5, Fig.3, and'illustrating the operating shaft in operating position;

Fig.6 is a plan View, looking d wnwardly 'along' the same line, Fig. 3;and v, Fig. '7 is an enlarged sectional view through the tracer alongthe line 11- 1, Fi 5. Q

The tracer forming the subject matter of the; present invention can bestbe explained by a. description. of the. technique of which it; forms 4Claims. (o1.- ga -sa remote, from a part. It may be assumed, as anexample, that a dental techniciamin his laboratory, possibly theoflice'of the dentist, is assisting in the preparationor fabricationof dentalplates in accordance with measurements and other instructions obtainedandsupplied' to him'by' the dntist'as' the result of his examination ofthe patients mouth. The cooperative procedure of the dentist and histechnician is as follows;

First the dentist prepares a pair of upper'and lower jaw impressions inany suitable'plaste'r or other material, by standard procedure,requiring neither illustration nor detailed description. Next, hepreparesthe usual'wax mush bite form (not shown) to simulate the .truebite rela?" tion 'of the two jawsyand also establish an arbi traryvertical spacing relation between them, as a basis from which to worklater on, as will appear I I The twoim'pressionsandfthe mush bite formare sent to 'the technicia'n who proceeds as fol- First, he fabricatestwo models (not/shown), from the'two' impressions. one for .each jaw.The models are complementary to the upper and lower jaw impressionsfurnished by the dentist and simulate .the upper jaw and palate and thelower. jaw respectively of the patient. These models are mounted on thehinged arms of the, usualarticulator (not shown) by means of which theymay be relatively moved to simulate ordi nary bite action. Base platemembers are then made conforming to the models. The upper platecomprises an impression Ill similar to-the impression made by thedentist and includes an integral central. portion I [la ,across thepalate. Ifhe lower plate comprises an impression ll adapted to fit thelower jaw of the patient. The plate members I0, ll, are temporary andmay be made of any suitable material for the. purpose; such as ahardening plaster or a plastic material- Each is a thin walledconcave-convex member accurately conformed to fit the corresponding jawmodel member on its concave faceand: curved smoothly on its convex face.

Assuming the two models attached to the articulator, the technicianadjusts the articulator arms to close the base members togetherupon themush .bite form, thus bringing them into exactly the same bite relationexisting when the plates l0, II as at I2, I20, and builds them up toconvert them into bite plates. The built up wax supplies to the baseplates material to temporarily take the place of the teeth to be appliedlater, and to support the soft tissues around the mouth and lips, and tolimit approach of the two jaws, in the model, to a position just a lit-,

tle short of that where the teeth will be in bite in detail. This heaccomplishes by imbedd ing the shank or head l5 of the tracer in wax orplaster Hlb applied to. the inner or concave .face of the upper platemember Ill as shown in Fig. 4.

He also applies or attaches to the lower plate member It, with wax orplaster, a thin flat metal plate I S, made for example of aluminum, andthe upper surface of which may be coated with colored paint or othermaterial to show scratch traces upon it.

All parts so far prepared are now returned to the dentist for furtheradjustment in the mouth of the patient.

But, before explaining that procedure, it may be well to here describethe particular embodiment of our tracer shown in the drawings solely forpurposes of illustration, it being understood that the invention is notlimited to this form but only within the scope of the claims appendedhereto.

'The tracer M of course is quite small and compact, because it goes intothe oral cavity and must not interfere with comfortable closing of thejaws. It comprises a body portion Ma of generally cylindrical formhaving a flat transverse face I! at one end and a reduced shank i8 atthe other end provided with aflange'd head l5 by means of which it maybe firmly and immovably imbedded in the securing wax or plaster. Thebody is hollowed out to provide an inner cavity 'or chamber 19 withinwhich is mounted a tracer member 20, the lower-"end of which protrudesthrough face I! and is pointed, as at 21. The upper 'end of saidtracer'lies within a reduced extension '22 of the chamber 19.

Suitable operating means is provided for adjusting the tracer member-29longitudinally or endw-ise'in said chamber in such manner as to vary thepositionof its pointedend. This *operating means may be'of any form, solong as the adjustment may be made while the tracer is within the oralcavity and does not interfere with-the form or position of-the softtissues, such as the lips. The itracer member moves 'in a straight linewhich is approximately normal to the 'occlusal plane which isroughlyindicated by the line 55 of Fig. 3.

In the form shown the tracer member 2D is 'a threaded screvv,longitudinally slott'edl alongone side 'toreceive the inner 'enizl of :aihea'dlessset screw :23, which prevents rotation of the screwbut-permits its endwise adjustment. On "the sorew is mounted aninternally threaded nut or actuating member in ithesformof aibevel'gear24 which meshes with -'a-.'similar gear 25 on the inner end of a shaft26 rotatably' mounted on a hori-- zontal axis in a plug 12:1 driven intoan =openingin the ibody wall. Shaft :ZS has a noncircular,

such as square, recess 28 in its outer exposed end to receive the likeinner end of a key shaft 29 by means of which the gearing may be turnedin either direction. When the tracer is molded into its 'fixed positionit, of course, is turned to such position that the recess 28 ispresented outwardly toward the mouth opening, preferabl in one of theends or corners of the opening, and a hole -'or aperture 30 is cut outor dug through the wax opposite said recess.

'- "The purposeyof pur tracer is to enable the dentist to relativelyadjust the bite plates of a pair, while they are properly co-related inthe oral cavity, in such manner as to secure or determine thatparticular vertical spacing between said plates which provides orproduces the desired, or them'os't'pleasing, appearance or externalcontour of the soft tissues, such as the lips. With age, the teeth weardown, so that later in life it may be desirable, in new plates, toappropriately increase the vertical spacing, While with the first set ofplates it'is equally desirable to initially determine the best relation.In either case the best results are secured only when the adjustment ismade while the bite plates are in the oral cavity. The plates andmodels, prepared by the technician, as described, are returned to thedentist. He inserts the bite plates in the mouth, as in Fig. 2, andpushes the square end of the key 29 between the lips and inserts itthrough opening 30 into the square driving recess 28, as in Fig. 1. Thenhe turns the key to adjust the tracer screw with its pointed endengaging the surface of the flat aluminum plate-16', as in Fig. '4. Theadjustment is continued by movement of the tracer screw up or down to anoptimum osition, in which the lips, relaxed or in repose, present themost desirable external contour or appearance, or where the bite 'iscomfortable to the patient, or by the criterion of the individualdentist.

The patient is then requested to move his jaws as though to grind histeeth, the eifec't being to cause the tracer point 2| "to mark orscratch upon plate [6 an arched line, the gothic arch, the apex of whichis at thecentral vertical axis of the jaws. This axis is usuallymarkedpermanently with a small hole 3i, Fig. 6, inte -whichthe pointed end ofthe tracer screw will extend.

After hole 3| is drilled the plates are again checked in the patientsmouth with point 2zl fin hole'3l, and-readjusted, if necessary.

The operating shaft is Withdrawn and the bite;

plates are temporarily secured together, or in fixed relation b means ofwax or plaster of Paris, and with them so secured, the two" plates,

as a unit, are removed from the mouth and returned to the technician inthat condition.

He secures the bite plates to the articulator arms as before. This isaccomplished by first mounting one bite plate, .say the lower, uponitsbase or body member, and then closing the other arm of the articulator,with the other body member, down upon the first, .to bite engagement.

The articulator closing stop is then adjusted to the technician to..pro-

they are conformed to and fitted upon the patients jaws the desiredexternal facial contour will be produced.

The key 29 may be made a permanent part of the tracer, such as by makingit a fixed part of gear 25 and its shaft 26, in which case it is moldedinto the wax and usually turned slightly as the wax hardens, to free itfor later operation.

What we claim is:

1. An lntra-oral tracer of the character described, comprising a bodymember externally of such shape as to enable it by molding to beattached in fixed position to a dental bite plate, a.

3. A tracer of the character described in claim 1, in which said bodymember is provided with an inner chamber, into which the tracer memberextends, and including operating connections between operator and tracermember enclosed within said chamber, said operator being detachablyconnected to said operating connections.

4. A tracer of the character described in claim 1 wherein means isprovided for causing said straight line movement of said tracer memberincluding a pair of coacting bevelled members one of which is mounted onsaid tracer member and the other of which has a detachable connectionwith said operator.

FAY E. SMITH. DELMAR LACER. CLARION B. McLEOD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,776,474 Messerman Sept. 23,1930 2,176,575 Sorenson Oct. 17, 1939

